Clutch Relay Circuit

The compressor clutch coil engages and disengages the compressor from the engine. When the PCM energizes the coil relay, it locks the clutch plate to the spinning pulley, causing the compressor shaft to spin. If the clutch is slipping or not engaging, inspect the circuit for shorts, resistance, and open circuits.

This question indicates a short to ground at point D of this circuit. This circuit is ground-controlled by the PCM. If there's a short to ground before the PCM, the clutch relay remains closed whenever the circuit is powered. This short to ground would cause the A/C clutch to stay engaged whenever the circuit is powered.

If the circuit were open at point D of this diagram, the A/C clutch wouldn't engage. This open is probably a break in the wire or the connector/pin leading from the relay to the PCM. If there were an intermittent condition where the clutch works one minute and not the next, suspect a loose plug or connection at the clutch, PCM, fuse, or the relay itself.